[cliffyk]

I already have a full exhaust and lts. So im hoping that the tb and cai will make more of a difference since i have that **** on already. I also have a 90mm maf that i got for 50 bucks.

You will need a new tune to use the 90 mm MAF. It's transfer curve is completely different than the stock 80 mm unit and without a retune the engine will run quite rich in open-loop (higher loads and WOT). However there is no need to use a 90 mm MAF on nearly any 4.6L 2V n/a bulld; the stock MAF can support up to 400 fwHP, 345 or so at the wheels...

The plenum is the weak link in the stock intake. Here are Accufab's flow bench numbers for the stock and number of aftermarket TBs and plenums. You can see that any aftermarket plenum with the stock 65 mm TB will outflow the stock plenum with a 75 mm TB. 70 mm is as big a TB as is needed for the 2V, and it has the advantage of providing higher charge velocity at WOT and high RPM.

 

[cliffyk]

So should i just buy a plenum? And not worry about the tb. Cuz from what i understand thats all it takes to acquire adequate air flow.

If cash is short then just get a plenum, however 'twas me I'd spend the other $100 bucks and get a 70 mm TB too.

Also get a tune/tuner. The stock tune is very conservative with uninspiring ignition timing and running very rich in open-loop, with AFRs dropping into the 11s at high loads and WOT. I have never loaded a tune into a dead stock GT without the owner coming back from the first drive with a big grin on their face. Tune it for the highest octane fuel you can get, the lousy 20¢ to 30¢ per gallon difference is only $3.00 to $4.50 extra per tankful, just drink a couple fewer beers or lattes and you've got it covered...